D&D seems to be played a number of different ways and designing a game that will please everyone is challenging, but I believe it's possible.
Couldn't the game be split up into 'meta-tiers' that have different design assumptions? I would propose that the 'prime material plane' be broken into 3 different planes; each with slightly different magical laws and use each as a connected setting for the game.
I would then release each meta-tier as a separate box set; much like what was done with BECMI; except that EACH metatier includes a character generation system that allows PCs to be rolled up for that level of play, quickly and efficiently.
Low level (1-5); The design goal of this metatier is to model the heroes found in most fantasy books. The setting (call it Holmgard) is gritty, dangerous and very low magic (indeed spells above 2nd level don't function on this plane because the magical weave is too weak to support them). Monsters are low level and disorganised Holmgard is humanocentric, 'grounded' and closely models the real world; think LoTR not anime. Humans and less fantastical races predominate and PCs advance, not by acquring magic items, but through 'training' to acquire intrinsic bonuses. Magic-items are extremely uncommon and cannot be bought and sold. The design assumptions at this metatier emphasise resource management and danger. Non-magical forms of healing should predominate and it should be possible to play the game without a healer at this meta-tier. Character generation should be very simple; starting with PCs as members of a class not unlike the NPC classes that were present in the DMG of 3.5E. The rest of character generation actually happens in play, as the PCs advance.
Medium Level (6-10); The design goal of this tier is to model film fantasy. At this level, the setting (Midgard) is much more fantastical and there are many more non-human PC races in the Midgard setting. An alternate character creation system would allow DMs and players to start playing at this level; bypassing the low-level meta-tier completely but the system is quick. In this tier, monsters are much more powerful, PC advancement is a mixture of magic items and training and resembles classic D&D most closely. Magic items can now be bought and sold and are much more common.
High level (11-20); The setting and playstyle at this level is almost a fantasy superheroes game. Magic items predominate as the means of advancement and many highly magical races are available as PCs; a third character generation system allows DMs and players to quickly generate PCs for this meta-tier, bypassing the first two.
If the designers did this then everyone could play D&D exactly how they want to; just by staying at the meta-tier and in the setting that supports that style of play. Those that want to do the 1-20 thing move through the settings.